The present invention is directed to improving the user interface in a data processing system employed for the generation of drawings or illustrations on a display screen. When a pointing device, such as a mouse, is used to indicate the position in the workspace of the display screen, a conventional selection mechanism designates or selects the graphical object closest to the indicated point, the cursor position at the time of selection. However, in conventional systems, the user's indication of a selection in a region of the workspace where multiple graphical objects coincide or overlap may easily result in the selection of an object not desired.
Heretofore, a number of patents and publications have disclosed techniques and devices suitable for editing and manipulating documents, the relevant portions of which may be briefly summarized as follows:
U.S. Pat. No. 5,315,313 to Shinagawa, issued May 24, 1994, discloses a figure electing device that permits a user to select a figure in the vicinity of a point indicated on a display screen. Fuzzy inference based upon fuzzy rules are employed to determine the figure designated by the pointing device.
In "Diagram Understanding: Associating Symbolic Descriptions with Images," IEEE Computer Society Workshop on Visual Languages, (1986), pp. 4-11, Montalvo teaches a paradigm for the discovery and validation of higher-level visual properties. The author recognizes the needs of users to select objects and properties by pointing and to input objects by drawing, and particularly, the endless possibilities of selecting one element from a set.
In "Formalizing the Figural: Aspects of a Foundation for Document Manipulation," Xerox Palo Alto Research Center, 1980-1990, Vol., No., (1993), pp. 132-38, Levy et al. describe a model to account for the graphical appearance of figures and windows with a graphical user interface. More specifically, the authors illustrate that an image configuration or display may be represented as a set of figures "floating" in 21/2 dimensional space, which by a process called rendering are flattened to produce a 2-dimensional visual field for display.
In "Eight-Sided Bounding Boxes," Xerox Disclosure Journal, Vol. 19, No. 1, (January/February 1994), pp. 75-76, Harrington teaches a method for determining which objects within a scene overlap.
In accordance with the present invention, there is provided a method for selecting an element, using a pointing device, from among a plurality of overlapping elements displayed in an image display plane of a data processing system, wherein the pointing device establishes a selection point in the image display plane and provides location information for the selection point, including the steps of:
determining coordinates of the selection point; PA1 identifying, based upon the coordinates, all elements having at least one point in common with the selection point; PA1 recognizing when plural elements have a point in common with the selection point; PA1 upon recognition of plural elements in common with the selection point, displaying, at a separate location of the image display, representations of the identified plural elements in a form suitable for enabling the selection thereof; and PA1 enabling the selection of one of the representations of the plural elements displayed at the separate location, wherein the selection of the representation also selects the associated one of the plural elements. PA1 a pointer interface for generating a pair of coordinates for the selection point; PA1 element identifying means, responsive to said pointer interface, for receiving the coordinate pair and, based upon the coordinates, identifying all graphical elements having at least one point in common with the selection point; PA1 control circuitry for determining when a plurality of identified graphical elements have a point in common with the selection point; PA1 a display window, for displaying at a separate location on the image display, representations of the identified plural graphical elements in a form suitable for enabling the selection thereof; and PA1 selection means, responsive to said coordinate determining means, for recognizing the selection of one of the representations of the plural graphical elements displayed at the separate location, wherein the selection of the representation also selects the associated one of the plural graphical elements.
In accordance with another aspect of the present invention, there is provided an apparatus for selecting a graphical element, using a pointing device, from among a plurality of overlapping graphical elements displayed in an image display plane in a data processing system, wherein the pointing device establishes a selection point in the image display plane and provides location information for the selection point, including:
One aspect of the invention is based on the observation of problems with conventional image editing systems. This aspect is based on the discovery of a technique that alleviates these problems by providing a second, improved visual representation of the overlapping graphical elements within a workspace and allowing the selection and manipulation of the respective overlap position (layer) of one or more of said elements by "selection" of the improved representation of the element(s).